Chronobiology may be briefly described as the study of temporal characteristics of biological systems. The objects of this biennial conference is o provide a forum for the members of the International Society for Chronobiology and for all others working in Chronobiology to present results of their work and to interact with experts at the forefront of knowledge in the field of biological rhythms. The Society is especially encouraging the participation of students and of new practitioners in the field. The meeting will provide an opportunity for scientists in the fields of psychology, psychiatry, mathematics, public health, statistics and quantitative chronobiology and chronobiological education to exchange views. In keeping with the broad nature of the discipline of chronobiology, a wide range of topics will be included on the program. One main theme of the meeting will be "Application of chronobiological concepts and techniques to maintaining a healthy organism, be it man, lower animal or plant". Emphasis will be placed on determining the most efficacious schedules for treating patients with drugs and determine the actual responses of model systems to such drugs during the execution of test protocols. Some sessions will address the development of methodology to determine how to interfere with rhythms of organisms harmful to man, domestic plants and animals or the environment while maintaining near normal rhythms in the hosts or beneficial species. Participants will address another theme, the mechanisms of regulation and maintenance of rhythms including genetic, neurohormonal,neuro-regulatory and hormonal aspects. Interplay between internal regulation and external synchronizers will be explored. Although the rhythms which have a periodicity of about 24 hors (circadian) will be the subjects of major discussions, rhythms with periodicity greater than 24 hours or less than 24 hours will be given ample consideration.